Matched Pair Telefunken (The Fisher labeled) Ecc83 12ax7 LongSmoothPlate Halo Getter Diamond Bottom Tubes TV7&Maxi Tested ANOS. Closely matched at ~4%.

Tested per user manual procedures on TV-7D/U recently calibrated by Dan Nelson (TV-7D/U calibration expert) (Documentation available upon request)

Passed all tests:

Shorts Tests: Passed

Mutual Conductance (GM)Test: 42 & 46 and 47 & 40 (49 = Average NOS and 32 = Good MINIMUM)

Gas (Grid Current)Test: Passed

Maxi-Preamp 2 tester results:

Tested noise (< 92 DB): Passed

Gain: (89.8 & 90.0 and 91.2 & 93.3) MU and side balance.

Transconductance : 1696 & 1787 and 1779 & 1570

Also tested in THD Guitar amp for performance and sound at operating voltage. Very good sounding low noise tube pair.

For the most reliable and comparable results, I try to test using both vintage and modern test equipment along with testing in amps when possible. Test results will vary between testers as it is not an exact science.

I recommend all vintage tube pins to be cleaned before usage for best performance.

Will combine shipping. I will send refund promptly once actual shipping cost is determined.

Given the fragile nature of tubes, they will we securely packaged for shipping. Please notify me of any issue or concerns once you receive the items so I can promptly address. Guaranteed not to be dead on arrival.

I have been on eBay for over 20 years.